Rotary pump



L. RLow ROTARY P March 4, 1

Filed Feb. 14, 1928 2 Sheats-Sheet 1 March 4,1930. 1,749,058

L. P. BARLOW ROTARY PUMP Filed Feb. 14, 1928 2 Sheets-Sheet 2 I jg leszrzfiazr Z030,

Patented Mar. 4, 1930 LESTER P. BARLOW, O! STAMFORD, CONNECTICUT ROTARY PUMP Application filed February 14, 1988. Serial No. 854,222.

This invention relates to rotary umps of the positive displacement type in w ich rollers are impelled around the inside of a chamber through the medium of a slotted rotor.

One object of my invention is to provide port means whereby the pressures about the rollers are so balanced and regulated that the rollers retain continuous sealing contact with the inner surface of the rotor chamber at all times during the operation of the pump,

thereb preventing leakagepast the rollers from the high to the lowpressure sides of the pump and also preventing self destruction of the pump by preventing hammering of the l1;ollers against the inner surface of the cham- Another object of m invention is to so dispose and arrange sai port means with-respect to the rotor slots that the porting action to and from the bottoms of the slots beneath the rollers will be in synchronism with the centrifugalforces set up in the rotation of the rotor and aid such forces to maintain the rollers in continuous sealin contact with the inner surface of said cham er.

Another object of my invention is to .provide the porting means with inner and outer interconnecting channels on both the low and high pressure sides of the pump and have the inner ports communicating with the bottoms of the rotor slots beneath the rollers and the outer ports communicating with the outer portions of the slots at the periphery of the rotor.

Another object of my invention is to provide these ports in stationary parts of the pump housing-and also so arrange the ports that arotor slot may move from the high to the low pressure sides of the pump without bridgingthe ports, and thus avoid loss of pressure as the slots pass between the high and low pressure ports.

Another object of my invention is to provide a race ring for the rollers and also to '45 have this ring bridge the intake and discharge chambers which are made inthe pump housing at the low and high pressure sides of the pump, respectively.

Another object of my invention is to relieve destructive hydraulicking as the rollers reach the end of the high pressure cycle by relieving the hydraulic ressure past the advancing side of the rol er by the inner port associated with the bottoms of the rotor slots.

The invention consists further in the matters hereinafter described and claimed.

In the accompanying drawings- Fig. 1 is a side view of a pump constructed in accordance with my invention;

Fig. 2 is a front view of the pump;

Fig. 3 is a view looking into the pump with the cover plate removed;

Fig. 4 is a vertical sectional view taken on line 4-4 of Fig. 1 with the rotor and rollers omitted to show the port arrangement;

Fig. 5 is a horizontal sectional view taken on line 55 of Fig. 4, with the rotor and its rollers in the rotor chamber;

Fig. 6 is a vertical sectional view taken on line 6-6 of Fig. 4:;

Fig. 7 is a vertical sectional view through the cover plate; and

Fig. 8 shows a feature to be hereinafter described.

In the drawings,'1 indicates the pump housing provided with a rotor chamber in which is fitted a stationary race-ring 2. Said ring has a tight fit in the housing and is made of a metal which has the best wearing characteristics for the purpose of the pump.

The housing 1 is closed on one side by a cover plate 3 which may be secured in place by fastening screws, as shown in the drawings. The other side of the housin is closed by an end Wall 4 which is prefera 1y an integral part of the housing. Located in the ring 2 is a cylindric rotor 5 keyed or otherwise fixed to a shaft 6 which extends through the end walls 3, 40f the housing and journaled therein, as illustrated in Fig. 5. The rotor 5 is smaller in diameter than the inside of the ring. This permits arranging the center of the rotor and shaft in slightly eccentric relation to the center of the ring so that the peripheral surface of the rotor may be brought close (almost in contact) to the inner surface of the ring on one side of the rotor while providing a relatively wide gap or clearance space between the rotor and the ring on the opposite side of the rotor, as

or to so as to reduce to the minimum the tendency shown in Fig. 3. The rotor 5 is provided with a multiplicity of radial slots 7 which are equally s aced about the circumference of the rotor an open outwardly at their outer ends through the cylindric periphery thereof so as to receive pistons in the form of rollers 8, 8 which are slightly smaller in diameter than the width of the slots so that the rollers may have freedom of movement therein and also permit the passage of liquid along the cylindrical surface of the roller from the outthe inner ends of the slots. In practice about three quarters of each roller surface is exposed to pressure on the pressure side of the pump, the pressure holding the rollers against the opposite sides of the slots and the race ring 2. This clearance is only very slight, and in small pumps only about .004 or .005 of an inch. In the drawings, I have shown the clearance exaggerated for illustrative purposes only. The rollers 8 may be made solid or hollow as desired.

- The inlet and discharge. ports 9, 10 of the pump extend through the body of the housing 1 on opposite sides of the rotor and open, respectively, into chambers 11, 12 provided in the housing on the outer side of the racering 2, as shown in Fig. 4. These chambers 11, 12 are wider than the race-ring 2, as shown in Fig. 5, so that the fluid medium handled by the pump may flow about the sides of the ring in passing through the pump. The ring 2 bridges these chambers and thus provides a continuous surface for the rollers 8 as they pass the chambers during the rotation of the rotor.

Provided in the inner surface of each end wall 3, 4 are two sets of inner and outer arcuate channels, there being a set of these channels at the inlet and discharge sides 9, 10, respectively, of the pump. The outer channels 13, 14 of both sets are arranged inside of the race-ring 2 and have communication around the sides of the ring with their respective chambers 11, 12. The inner channels 15, 16 in each and have communication with their respective outer channels 13, 14 by passageways 17, 18, respectively. The channels 13 are considerably longer than the chamber 11 and extend to within close proximity (region A, Fig. 4) to where the rotor 5 and ring 2 are the closest together, so as to afford the longest possible period of feeding the low pressure side of the pump from the inlet 9. The opposite ends of the channels 13 and chamber 11 register and provide the cut-off between the high and low pressure sides of the pump. The channels 14 on the discharge side of the pump extend relatively close to the closest point between the rotor and the race-ring 2 to hydraulic and permit the minimum amount of liquid to be displaced past the rollers 8 as they approach this region A. This disend wall are close to the shaft 6.

placed fluid finds outlet around the front.

sides of the rollers-8 to the bottoms of their slots 7 and into the inner channels 16 from which it may flow into thedischarge chamber 12 and relieve the pressure at the rollers as they advance to the high point of the rotor. (See Fig. 3.) When working with non-compressible liquids, such as oil or water, the race-ring 2 would be scored and distorted if these ressures could not be relieved even though tlie film of liquid would not be more than .001 of an inch thick.

The inner channels 16 of the high pressure sets extend to close proximity to the cut-off of the inlet side of the pump so that said inner channels 16 will communicate with the bottom of the slot 7 of the next advancing roller 8 immediately that such roller passes the cut-off, and thus pressure from the hi h pressure side of the pump acts on the un er side of the roller so that it will be maintained against the race-ring 2 and not be driven from the race and into the slot by the high pressure on the discharge side with which it comes in contact on passing the cut-off. These inner channels 16 extend far enough around the pump so as to maintain a pressure on the under sides of the rollers from the cut-off of the intake to the beginning of the same as established by the outer channels 13 on the low pressure side of the pump. In this way the pressures on the driving and under sides of the rollers are balanced, and as a result the rollers are maintained by pressure in contact with the inner surface of the ring 2.

As shown in Fig. 4, the inner channel 15 is considerably shorter than the associated inner channel 16, and the opposed ends of these channels are spaced apart a distance slightly greater than or approximately the width of a rotor slot 7 so that when the slots are central between the channels, the slots are cut off from both, and thus the high pressure channel 16 can not discharge through the slot to the low pressure channel 15. (See Fig. 8.) The relative lengthsof'these inner and outer chambers 15, 16 depend on the number of rollers which are employed in the pump. As the number of rollers are increased the comparative lengths of these slots more or less approach an e ual value, the spacing between the ends 0 the channels being always preferably slightly greater than the width of a rotor slot so as to accomplish the purpose set forth.

By carryin the inner channels 16 beyond the cut-off en s of the outer channels 14, the relief of pressure on the driving sides of the rollers is not only secured, as heretofore mentioned, but the spaces in the bottoms of the slots under the rollers as they tend to increase by the rollers advancing toward the inlet side of the pump are supplied with pressure from the inner channels 16, and thus the rollers will be maintained against the inner surface of the race-ring 2 without depending on any centrifugal forces set up on the rotation of the rotor until the roller slot passes the cutoff ends of the inner channels 16. When this happens, the bottom of the slot 7 of the advancin roller is brought into communication with the inner channels 15 on the low pressure side of the pump and fluids may flow beneath the roller to relieve any partial vacuum formed as the roller is moved outward against the ring 2 by centrifugal forces. This condition continues until the slots 7 of the advancing rollers pass the channels 15 at the cut-oil ends thereof, whereupon the slots are subjected to the high pressure on the outlet side of the pump by registration with the inner channels 16, as heretofore described. While I have mentioned that the opposed ends of the inner channels 15, 16 arerspaced apart preferably slightly greater than the width of a rotor slot 7, the spacing for ideal conditions would be the exact width of a rotor slot. For heavy fluids, the pump would function even though the rotor slots 7 were slightly wider than the spacing between the opposed ends of the channels. In manufacturing the pumps, I find it preferable to have the rotor slots slightly less than the distance between the opposed ends of the channels. The balanced pressure condition on the piston rollers 8 throughout the entire cycle of rotary movement of the rotor prevents the pistons losing continuous sealing contact with the inner surface of the rotor chamber.

The rotor slots have the same dimensions, and

where the opposed ends of the inner channels intersect the slots, said ends have the same contour as the portions of the slots intersected thereby.

The positive displacement rotary type pump is the ideal form of pump if it can be made to function with the high efliciency of the reciprocating piston type of pump. In my design I have reached that efiiciency, due to the fact that the moving parts and the chamber of my pump are in positive contact and remain in contact over a long life of the pump due to the fact that they can move to the point of contact regardless of the amount of wear'that may be developed either in the chamber or on the rollers or in the rotor. Another feature of this type of pump is that it can operate either at exceedingly slow speed and still pump at pressure, or can operate at extremelyhigh speed with the same efliciency, thus making it acceptable when directly driven by a variable speed machine, such as internal combustion engines in automobiles, etc. Furthermore, my type of pump with the improved ports of my design makes possible high rotary speeds without vibration and with the minimum amount of noise. Furthermore, the pump functions without the use of valves, the slots in the rotor functioning as cut-in and cut-out at the ends of the various ports in properly timed relation with the action of the pump. Full advantage is taken of the centrifugal forces set up in the rotation of the rotor in maintaining the roller pistons in the continuous sealing contact with the race ring by co-. ordinating and synchronizing the flow and the pressure of the fluids about the rollers during the entire rotary cycle of the pump. ,Also the pump has the very minimum of movmg parts, and these parts are extremely rugged and have exceedingly long life. Although the pump functions with positive displacement, solid particles may be carried through the pump, the rollers rolling over them, the design of pump being such that the rollers may pass over. The pump of my invention permits of extreme rotary speeds at a high volume of output, making possible a very light weight pump of large capacity and small size where the minimum of space so demands. It is particularly applicable for use as water, oil, and fuel pumps on aeroplanes, where minimum weight, size, and high capacity are desired.

The details of structure and arrangement of parts may be variously changed and modified without departing from the spirit and scope of my invention.

I claim as my invention:

1. In a rotary pump, a housing having a rotor chamber with intake and discharge openings, a rotor in said chamber and having radial slots, roller pistons loosely fitting in said slots to allow for an equalization of the fluid pressure on the entire high pressure side of the pistons during the pumping stroke, and fluid passage means permitting the fluid to be conducted away from the advancing side of the pistons as they pass over the high point of the rotor to prevent trapping of fluid in advance of the pistons in the rotor chamber.

2. A rotary pump comprising a housing having a rotor chamber with intake and dis-J charge openings, a rotor in said chamber having radial slots of substantially the same width, a piston in each of said slots for displacing fluid through said chamber, and inner and outer interconnected channels in said housing, the outer channels connecting with the intake and discharge openings respectively, and the inner channels connecting with the slots beneath the pistons, the adjacent ends of the inner channels being opposed and spaeedapart approximately the width of a rotor slot.

3. A rotary pump comprising a housing having a rotor chamber with intake and discharge openings, a rotor in said chamber having radial slots, a piston in each of said slots for displacing fluid through said chamber, and inner and outer interconnecting channels in said housing with the outer channels its of the rotor for displacing flui .connected with y the intake and discharge openings respectively, the inner channel on the intake side of the pump corhiecting with tion and the inner channel on the discharge side of the pump connecting with the inner endsof the slots beneath the pistons to permit a reversible .flow of liquid under pressure out of and into said slots to retain. pressure beneath the pistons during the pumping stroke and as the pistons pass the 4. A rotary pump, comprising a housing having a rotor chamber with intake and discharge openings, a rotor in said chamber having radial slots opening through an end of the rotor, a piston in each of said slots for displacing fluid through said chamber, and inner and outer interconnected channels in said housing at theend of the rotor opposite the open endsof the slots, the outer channels connecting with the intake and discharge openings respectively and the inner channels connecting with the slots beneath the pistons through the openends ofthe slots throughout the entire rotary cycle of the rotor.

5. A rotary pump, comprising a housing having a rotor chamber with intake and discharge openings, a rotor in said chamber having radial slots opening through the opposite ends of the rotor, a iston in each of said slots through said chamber, and inner and outer interconnected channels in the end walls of the housing opposite the ends of the rotor and opening into the slots through the adjacent ends thereof, the outer channels connecting with the intake and discharge openings respectively, and the inner channels connecting with the slots beneath the pistons through the open ends of the slots throughout the entire rotary cycle of the rotor.

6. A rotary pump, comprising a-housing having a rotor chamber with intake and discharge openings, a rotor eccentrically mounted in said chamber and having radial slots, a piston in each of said slots for displacing fluid through said chamber, and inner and outer interconnected channels in said housing, the outer channels connecting with the intake and discharge openings respectively, and the inner channels connecting with the slots beneath the pistons throughout the entire rotary cycle of the rotor so that the inner channels on the discharge side of the pump will maintain pressurebeneath the pistons as they pass from the discharge to the intake sides of the pump at the highest point of the rotor.

7. A rotarypump, comprising a housing having a rotor chamber withintake and discharge openings, a rotor in said chamber having radial slots of substantially the same high pointsame.

dimensions and opening through an end of two sets of inner and outer interconnected channels in the housing at the end of the rotor opposite the open ends of the slots, there being a set of channels on the intake side of the pump and a set of channels on the discharge side of the pump, the outer channels of each set connecting with the intake and discharge openings respectively, the innerchannels of each set connectin with the slots beneath the pistons through t e open ends of the slots,

said sets of channels being arranged with the adjacent ends of the inner and outer channels opposed and with the opposed ends of the inner channels spaced apart approximately the width of. the slots where they ntersect the 8. A rotary pump, comprising a'housing having a rotor chamber with intake and dis charge openings, a rotor in said chamber having radial slots, a piston in each of said 'slots for displacing fluid through said chamber, and two sets of port means in the housing, one port means connecting the intake opening with the bottoms of the slots on the intake side of the pump, and the other port means connecting the discharge opening with the bottoms of the slots on the discharge side of.

the pump, said port means being constructed and arranged to provide for the pistons having continuous sealing contact with the inner surface of the chamber during the entire rotary cycle of the rotor.

9. A rotary pump, comprising a housing having intake and discharge openings, a stationary race ring fitted in said housing, a rotor eccentrically mounted within said ring and having radial slots opening through the periphery of the rotor and at least one end of the same, pistons loosely'fitted in said slots and working against the inner surface of said ring for displacing fluid through the pump, said housing having recesses formed therein onthe outer side of said rin one recess for each of said openingsan nected therewith, and port means in the housing oppositethe open ends of the slots and connected with the respective recesses about at least one edge of said ring, said port means being disposed to conduct fluid to and from the bottoms of the slots beneath the pistons in synchronism with and aiding the centrifugalforces set up in the rotation of the rotor so as to maintain the pistons in continuous sealing contact with the raceway therein, a rotor eccentrically mounted in said racewa and having radial slots opening throng the periphery of the rotor and at least one end of the same, a shaft connected with the rotor whereby it may be rotated, pistons loosely fitting in said slots and working against said raceway for displacing fluid through the pump, said housing havin intake and discharge openings for-said c amber, and port means in the housing op osite the open ends of the slots and connecte with respective intake and discharge openings, said port means being disposed to conduct fluid to and from the bottoms of the slots beneath the pistons in synchronism with and aiding the centrifugal forces set up in the rotation of the rotor so as to maintain the pistons in continuous sealing contact with the raceway throughout the entire rotation of the rotor.

12. A rotary pump, having inlet and discharge openings and comprising a cylindrical raceway, a rotor eccentrically mounted within the raceway having radial slots, pistons movable in said slots, means for rotating the rotor to generate centrifugal force tending to hold the pistons in continuous contact with the raceway, and port means connected with the respective intake and discharge sides of the pump and disposed to conduct fluid to or from the slots beneath the pistons through the entire rotary cycle of the rotor to aid the centrifugal force to hold the pistons in continuous sealing contact with the raceway.

13. In a rotary pump, the combination of a chamber, a rotor in said chamber and having radial slots, pistons working in said slots, means allowing the pistons to have continuous sealing contact with the inner surface of said chamber during the operation of the pump, said means comprising channels which admit fluid from the high pressure side of the pump to the slots beneath the pistons during the movement of the pistons through the entire pressure side of the pump and a portion of the lower pressure side of the pump, and channels which connect, the slots beneath the pistons with the remaining low pressure side of the pump during the movement of the pistons through the low pressure side of the pump to supply fluid beneath the pistons so that during the driving portion of its movement the piston will be forced outward, and during the remainmg portion of its movement the efi'ect of suctlon on the piston will be prevented.

a 1%. A rotary pum comprising a'housing havmg a rotor cham or with intake and discharge openings, port means connected with Stud openings and having intake and discharge channels, a rotor in said chamber and having radial slots, a piston in each slot, said slots being so spaced that when an advanc- 1ng piston is at the beginning of the discharge channel the next following piston will be approximately at the closing end of the inlet channel, and port means for then transferring the bottom of the slot of the last named piston from the influence of the low pressure on the intake side of the pump to the influence of the high pressure on the discharge side of the pump as said last named piston passes from the closing end of said inlet channel.

15. A rotary pump, comprising a housing having a rotor chamber with intake and discharge openings, said housing having end walls closing the opposite sides of the chamber, a rotor eccentrically mounted in said chamber between said end walls, said rotor having radial slots of substantially the same width and opening through the periphery of the rotor and through the ends of the same, and a piston in each of said slots, said end walls having intake and discharge channels formed therein at the ends of the rotor opposite the open ends of said slots, said channels havin their adjacent ends opposed and separated y the intervening sections of said end walls a distance approximately equal to the width of a rotor slot, said intervening sections forming the end of the discharge channel and the beginning of the intake channel respectively.

16. A rotary pump, comprising ahousing having a rotor chamber with intake and discharge openings, and provided with intake and discharge channels, a rotor in said chamber and having radial slots, a piston in each slot, said slots and channels being so spaced with respect to each other that when an advancing piston is at the beginning of the discharge channel the next following piston will be approximately at the closing end of the inlet channel, and port means arranged to simultaneously connect the bottom of the slot of the last named piston with the dischar e side of the pump and cut ofl the slot with t e intake side of the pump.

17 A rotary pump, comprising a housing having a rotor chamber with intake and discharge openings, a rotor in said chamber and having radial slots, a piston in each of said slots for displacing fluid through said chamber, and inner and outer interconnected channels in said housing on the intake and discharge sides of the pump, the outer channels III connecting with the intake and discharge openings respectively, and the inner channels connecting with the slots beneath the pistons,

the inner channel on the intake side of the pump bein of such length as to provide con-- nection wit the piston ots during the movement of a piston over the'entire length of the intake opening and the inner channel on the discharge side of the pump being of su h a length as to piston slots stroke of the pump and a portion at ginning of the intake stroke.

rovide connection with he uring the entire discharge the be- In testimony whereof I aflix my si ature. I

LESTER P. BAR OW.

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